Methane throughout the atmosphere of the warm exoplanet WASP-80b.

The abundances of main carbon- and oxygen-bearing gases in the atmospheres of giant exoplanets provide insights into atmospheric chemistry and planet formation processes1,2. Thermochemistry suggests that methane (CH4) should be the dominant carbon-bearing species below about 1,000 K over a range of plausible atmospheric compositions3; this is the case for the solar system planets4 and has been confirmed in the atmospheres of brown dwarfs and self-luminous, directly imaged exoplanets5. However, CH4 has not yet been definitively detected with space-based spectroscopy in the atmosphere of a transiting exoplanet6-11, but a few detections have been made with ground-based, high-resolution transit spectroscopy12,13 including a tentative detection for WASP-80b (ref. 14). Here we report transmission and emission spectra spanning 2.4-4.0 µm of the 825 K warm Jupiter WASP-80b taken with the NIRCam instrument of the JWST, both of which show strong evidence of CH4 at greater than 6σ significance. The derived CH4 abundances from both viewing geometries are consistent with each other and with solar to sub-solar C/O and around five times solar metallicity, which is consistent with theoretical predictions15-17.

Photochemically produced SO2 in the atmosphere of WASP-39b.

Photochemistry is a fundamental process of planetary atmospheres that regulates the atmospheric composition and stability1. However, no unambiguous photochemical products have been detected in exoplanet atmospheres so far. Recent observations from the JWST Transiting Exoplanet Community Early Release Science Program2,3 found a spectral absorption feature at 4.05 µm arising from sulfur dioxide (SO2) in the atmosphere of WASP-39b. WASP-39b is a 1.27-Jupiter-radii, Saturn-mass (0.28 MJ) gas giant exoplanet orbiting a Sun-like star with an equilibrium temperature of around 1,100 K (ref. 4). The most plausible way of generating SO2 in such an atmosphere is through photochemical processes5,6. Here we show that the SO2 distribution computed by a suite of photochemical models robustly explains the 4.05-µm spectral feature identified by JWST transmission observations7 with NIRSpec PRISM (2.7σ)8 and G395H (4.5σ)9. SO2 is produced by successive oxidation of sulfur radicals freed when hydrogen sulfide (H2S) is destroyed. The sensitivity of the SO2 feature to the enrichment of the atmosphere by heavy elements (metallicity) suggests that it can be used as a tracer of atmospheric properties, with WASP-39b exhibiting an inferred metallicity of about 10× solar. We further point out that SO2 also shows observable features at ultraviolet and thermal infrared wavelengths not available from the existing observations.

[Endoscopic variceal ligation and percutaneous transhepatic obliteration difficulty in esophageal variceal bleeding: a case report].

A 48-year-old male patient with a history of alcoholic cirrhosis was admitted to our hospital due to hematemesis with a 7-day history of melena. Emergency esophagogastroduodenoscopy revealed esophageal variceal bleeding. We attempted hemostasis with endoscopic variceal ligation (EVL). The esophageal mucosa was not aspirated into the EVL device although the patient had no history of endoscopic injection sclerotherapy or EVL. Percutaneous transhepatic obliteration (PTO) was performed and esophageal variceal bleeding was successfully hemostasis. PTO is a viable option for refractory esophageal bleeding.

Early Release Science of the exoplanet WASP-39b with JWST NIRISS.

The Saturn-mass exoplanet WASP-39b has been the subject of extensive efforts to determine its atmospheric properties using transmission spectroscopy1-4. However, these efforts have been hampered by modelling degeneracies between composition and cloud properties that are caused by limited data quality5-9. Here we present the transmission spectrum of WASP-39b obtained using the Single-Object Slitless Spectroscopy (SOSS) mode of the Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument on the JWST. This spectrum spans 0.6-2.8 µm in wavelength and shows several water-absorption bands, the potassium resonance doublet and signatures of clouds. The precision and broad wavelength coverage of NIRISS/SOSS allows us to break model degeneracies between cloud properties and the atmospheric composition of WASP-39b, favouring a heavy-element enhancement ('metallicity') of about 10-30 times the solar value, a sub-solar carbon-to-oxygen (C/O) ratio and a solar-to-super-solar potassium-to-oxygen (K/O) ratio. The observations are also best explained by wavelength-dependent, non-grey clouds with inhomogeneous coverageof the planet's terminator.

Early Release Science of the exoplanet WASP-39b with JWST NIRCam.

Measuring the metallicity and carbon-to-oxygen (C/O) ratio in exoplanet atmospheres is a fundamental step towards constraining the dominant chemical processes at work and, if in equilibrium, revealing planet formation histories. Transmission spectroscopy (for example, refs. 1,2) provides the necessary means by constraining the abundances of oxygen- and carbon-bearing species; however, this requires broad wavelength coverage, moderate spectral resolution and high precision, which, together, are not achievable with previous observatories. Now that JWST has commenced science operations, we are able to observe exoplanets at previously uncharted wavelengths and spectral resolutions. Here we report time-series observations of the transiting exoplanet WASP-39b using JWST's Near InfraRed Camera (NIRCam). The long-wavelength spectroscopic and short-wavelength photometric light curves span 2.0-4.0 micrometres, exhibit minimal systematics and reveal well defined molecular absorption features in the planet's spectrum. Specifically, we detect gaseous water in the atmosphere and place an upper limit on the abundance of methane. The otherwise prominent carbon dioxide feature at 2.8 micrometres is largely masked by water. The best-fit chemical equilibrium models favour an atmospheric metallicity of 1-100-times solar (that is, an enrichment of elements heavier than helium relative to the Sun) and a substellar C/O ratio. The inferred high metallicity and low C/O ratio may indicate significant accretion of solid materials during planet formation (for example, refs. 3,4,) or disequilibrium processes in the upper atmosphere (for example, refs. 5,6).

[A case of refractory ascites due to splenic arteriovenous fistula appeared during the course of observation and cured by embolization therapy].

This is a case of a 61-year-old female who presented to our hospital with liver dysfunction without any symptoms. She was diagnosed with splenic arteriovenous fistula. About 8 months later, she visited the hospital again due to abdominal distention and diarrhea. Computerized tomography (CT) revealed splenic aneurysm, dilated splenic vein enhanced in the arterial phase, ascites, and intestinal edema. We considered that these findings were caused by portal hypertension due to splenic arteriovenous fistula. The splenic aneurysm was managed with coil embolization. Completion arteriography revealed the absence of flow into the splenic arteriovenous fistula. Surveillance CT scans at 2 months post-procedure confirmed complete occlusion of the aneurysm and arteriovenous fistula. There was no evidence of splenic infarction. The patient remained asymptomatic 1 year post-procedure. Asymptomatic splenic arteriovenous fistula is rare and needs immediate treatment due to the high probability of deterioration.

Determination of body volume in normal adults and in patients with cerebral palsy by the sulfur hexafluoride (SF6 ) dilution technique.

This study sought to establish body volume measurement by the sulfur hexafluoride (SF6 ) dilution technique and to assess the body composition of healthy subjects and patients with the complications of cerebral palsy and mental retardation. Sixty-six healthy males and females ranging in age from 18 to 41 years and 10 patients with the complications ranging in age from 23 to 34 years participated in the study. The SF6 dilution method determines absolute body volumes by measuring the SF6 concentration inside a closed chamber containing the subjects. No detectable deviations were indicated between the body volume measured by SF6 and the volume determined by underwater weighing (r = 0.999). Body volume for patients with complications was also successfully assessed by the SF6 technique. All 10 subjects were short, but body composition measures were within normal ranges except for two obese females. Inactivity was suggested as a relevant factor for the excess adiposity. Thus, this new method of measuring body volume offers promising possibilities for future research in body composition, especially for application in clinical practice. © 1994 Wiley-Liss, Inc.